Effects of Political Bias and Reliability on Temporal User Engagement with News Articles Shared on Facebook.

The reliability and political bias differ substantially between news articles published on the Internet. Recent research has examined how these two variables impact user engagement on Facebook, reflected by measures like the volume of shares, likes, and other interactions. However, most of this research is based on the ratings of publishers (not news articles), considers only bias or reliability (not combined), focuses on a limited set of user interactions, and ignores the users' engagement dynamics over time. To address these shortcomings, this paper presents a temporal study of user interactions with a large set of labeled news articles capturing the temporal user engagement dynamics, bias, and reliability ratings of each news article. For the analysis, we use the public Facebook posts sharing these articles and all user interactions observed over time for those posts. Using a broad range of bias/reliability categories, we then study how the bias and reliability of news articles impact users' engagement and how it changes as posts become older. Our findings show that the temporal interaction level is best captured when bias, reliability, time, and interaction type are evaluated jointly. We highlight many statistically significant disparities in the temporal engagement patterns (as seen across several interaction types) for different bias-reliability categories. The shared insights into engagement dynamics can benefit both publishers (to augment their temporal interaction prediction models) and moderators (to adjust efforts to post category and lifecycle stage).